Three-dimensional (3D) object fabrication techniques, such as solid freeform fabrication (SFF), allow a 3D object to be built layer-by-layer or point-by-point without using a pre-shaped tool (die or mold). Typically, data representing the geometry or shape of an object to be fabricated are used to control a fabrication tool to build the object.
Solid Freeform Fabrication (SFF) is a general term for using one of several technologies to create three-dimensional objects such as prototype parts, models, and working tools. Solid freeform fabrication is, for example, an additive process in which an object, which is described by computer readable data, is automatically built, usually layer-by-layer, from base materials.
Several principal forms of solid freeform fabrication involve a liquid ejection process. There are two main types of solid freeform fabrication that use liquid-ejection: binder-jetting systems and bulk jetting systems.
Binder-jetting systems create objects by ejecting a binder onto a flat bed of powdered build material. Each powder layer may be dispensed or spread as a dry powder or a slurry. Wherever the binder is selectively ejected into the powder layer, the powder is bound into a cross section or layer of the object being formed.
Bulk-jetting systems generate objects by ejecting a solidifiable build material and a solidifiable support material on a platform. The support material, which is temporary in nature, is dispensed to enable overhangs in the object and can be of the same or different material from the object.
In both cases, fabrication is typically performed layer-by-layer, with each layer representing another cross section of the final desired object. Adjacent layers are adhered to one another in a predetermined pattern to build up the desired object.
In addition to selectively forming each layer of the desired object, solid freeform fabrication systems can provide a color or color pattern on each layer of the object. In binder-jetting systems, the binder may be colored such that the functions of binding and coloring are integrated. In bulk-jetting systems, the build material may be colored.
Inkjet technology can be employed in which a number of differently colored inks are selectively ejected from the nozzles of a liquid ejection apparatus and blended on the build material to provide a full spectrum of colors. Often, the liquid ejection apparatus consists of multiple printheads, each ejecting a different base-colored binder or build material, such as cyan, magenta, yellow, black, and/or clear. On each individual layer, conventional two-dimensional multi-pass color techniques and half-toning algorithms can be used to hide defects and achieve a broad range of desired color hues.
However, most 3D printing technologies do not have color capability due to the technical challenges involved. Even in those cases where it is technically possible, producing full-color parts adds considerable expense.
Today, 3D digital fabrication (Rapid Prototyping) is primarily used by design engineers. These engineers typically use service bureau technology, such as stereolithography, to make rapid prototypes of their designs. Three-dimensional Rapid Prototyping equipment, as it now exists, costs $30,000 to $3,000,000 and can be expensive and complicated to operate. In addition, due to the messes, odors and noise that typically accompany known 3D digital fabrication processes, these machines are not appropriate for use in most office or home environments. Current market solutions to reduce costs have resulted in machines that are extremely slow, or processes that are complex and messy.
Laminated Object Manufacturing, a particular type of 3D digital fabrication, has additional disadvantages including the difficult removal of the excess build material which surrounds the created 3D object. In Laminated Object Manufacturing, excess build material is typically removed by slicing it into small cubes so it can be manually broken loose from the object surface. This process does not work well on partially-enclosed areas, and the material does not separate from horizontal parting lines.
Thus, it would be useful to be able to provide inexpensive 3D object fabrication devices, processes and materials that are suitable for both office and home environments. In particular, it would be helpful to be able to provide input materials to such devices while avoiding the safety hazards or cleanliness issues associated with the powders and liquids that are processed by many current machines. It would also be helpful to be able to provide the ability to remove excess unbonded material and/or materials from recessed and complex shapes without having to use dangerous chemicals.
It would also be helpful if such fabrication devices were as accessible and compact in size as a desktop printer. Moreover, it would be useful and cost effective if such devices included inexpensive and readily available components. It would also be desirable if such devices could operate significantly faster than current low-cost systems, e.g., current systems that rely on a single dispense nozzle.
It would also be useful to be able to provide a 3D object fabrication device that accommodates a variety of different types of media, such as media of different types and sizes, media formed from different types of materials, etc.
Additionally, it would be useful to be able to provide 3D object fabrication devices and processes that employ printing methods, such as inkjet printing, to form full-color 3D objects.